In flashback, New York nightclub pianist Al Roberts hitchhikes to Hollywood to join his girl Sue. On a rainy night, the sleazy gambler he’s riding with mysteriously dies; afraid of the police, Roberts takes the man’s identity. But thanks to a blackmailing dame, Roberts’ every move plunges him deeper into trouble. (imdb)

Seymour is a young man who works in a flower store. He manages to create a carnivorous plant that feeds on human flesh. Nobody knows about it, so Seymour and the plant become good “friends”. The plant needs food to grow up, so it convinces him to start killing people. A very young Jack Nicholson also appears in a small role. (imdb)